Abrasion resistant casting alloy for corrosive applications

Abstract

Disclosed is an abrasion corrosion resistant casting alloy which is readily machinable and of an approximately 50/50 mixture of austenite and ferrite obtained by uniquely heat treating a new thirty percent (30%) chromium, five percent (5%) manganese, three percent (3%) silicon, two percent (2%) molybdenum, one and one half percent (11/2%) copper plus additions of titanium, vanadium, carbon and nitrogen.

I claim: 
     
       1. An alloy composed of the following range of chemistry of critical elements:   ______________________________________                                    
C         Mn     Si     Cr   Cu   N   V    Ti  Mo                         
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% min. 0.1    3.0    1.0  26.0 1.0  0.3 0.5  0.5 1.0                      
% max. 0.5    7.0    5.0  34.0 2.0  0.7 1.5  1.5 3.0                      
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     with the balance being Fe; and said alloy having the following range of heat treatment:   subjecting said alloy to a solution treatment at 2050° F. (1121° C.) to 2250° F. (1232° C.) for 1 hour per inch of thickness followed by a suitable quench, or accelerated air cool; followed by   heating the alloy to 1600° F. (871° C.) to 1800° F. (982° C.) and soaking the alloy for 6 hours; followed by   furnace cooling of the alloy from the soaking temperature at a maximum rate of 50° F./hour to the range of 1100° F. (593° C.) to 1200° F. (982° C.) followed by cooling of the alloy in still air.   
     
     
       2. An alloy consisting of the following preferred range of chemistry of critical elements:   ______________________________________                                    
C         Mn     Si     Cr   Cu   N   V    Ti  Mo                         
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% min. 0.2    4.0    2.0  28.0 1.3  0.4 0.8  0.8 1.5                      
% max. 0.4    6.0    4.0  32.0 1.7  0.6 1.2  1.2 2.5                      
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     with the balance being Fe; and said alloy having the following range of heat treatment:   subjecting said alloy to a solution treatment at 2050° F. (1121° C.) to 2250° F. (1232° C.) for 1 hour per inch of thickness followed by a suitable quench or accelerated air cool; followed by   heating the alloy to 1600° F. (871° C.) to 1800° F. (982° C.) and soaking the alloy for 6 hours followed by   furnace cooling of the alloy from the soaking temperature at a maximum rate of 50° F./hour to the range of 1100° F. (593° C.) to 1200° F. (892° C.) followed by cooling of the alloy in still air.   
     
     
       3. An abrasion corrosion resistant casting alloy consisting of the following chemistry of critical elements:   ______________________________________                                    
C     Mn     Si      Cr   Cu    N   V     Ti  Mo                          
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0.3   5.0    3.0     30.0 1.5   0.5 1.0   1.0 2.0                         
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     with the balance being Fe; and said alloy having the following range of heat treatment:   subjecting said alloy to a solution treatment at 2050° F. (1121° C.) to 2250° F. (1232° C.) for 1 hour per inch of thickness followed by a suitable oil quench, or accelerated air cool; followed by   heating the alloy to 1600° F. (871° C.) to 1800° F. (982° C.) and soaking the alloy for 6 hours; followed by   furance cooling of the alloy from the soaking temperature at a maximum rate of 50° F./hour to the range of 1100° F. (593° C.) to 1200° F. (982° C.) followed by cooling of the alloy in still air.   
     
     
       4. An alloy according to claim 1 having been subjected to the following specific heat treatment: solution treating the alloy at 2125° F. (1163° C.) for 1 hour per inch of thickness followed by an oil quench or accelerated air cool; followed by   heating to 1700° F. (927° C.) for 6 hours; followed by   furnace cooling from 1700° F. (927° C.) at 50° F./hour to 1125° F. (607° C.); followed by cooling the alloy in still air.   
     
     
       5. An alloy according to claim 2 having been subjected to the following specific heat treatment: solution treating the alloy at 2125° F. (1163° C.) for 1 hour per inch of thickness followed by an oil quench or accelerated air cool; followed by   heating to 1700° F. (927° C.) for 6 hours; followed by   furnace cooling from 1700° F. (927° C.) at 50° F./hour to 1125° F. (607° C.); followed by cooling the alloy in still air.   
     
     
       6. An alloy according to claim 3 having been subjected to the following specific heat treatment: solution treating the alloy at 2125° F. (1163° C.) for 1 hour per inch of thickness followed by an oil quench or accelerated air cool; followed by   heating to 1700° F. (927° C.) for 6 hours; followed by   furnace cooling from 1700° F. (927° C.) at 50° F./hour to 1125° F. (607° C.); followed by cooling the alloy in still air.   
     
     
       7. An abrasion-corrosion resistant casting alloy according to claim 3 wherein said alloy is in the form of a casting. 
     
     
       8. An abrasion-corrosion resistant casting according to claim 7, wherein said casting is in the form of a pump casing. 
     
     
       9. An alloy according to claim 1 wherein said alloy is in the form of a casting. 
     
     
       10. An alloy according to claim 9 wherein said casting is in the form of a pump casing.